1. Field of the Invention
This invention relates generally to facsimile machines. More particularly, it relates to methods and apparatus for improving the intelligence of a facsimile machine, particularly with respect to a facsimile machine which is to be operated on a telephone line shared with a separate telephone or other telephonic device.
2. Background
Facsimile (FAX) machines have become an essential communication device in today's offices and homes. In a general sense, FAX machines allow images to be transmitted from one FAX machine for printing at another FAX machine using a respective telephone line to a respective central office of the public switched telephone network (PSTN).
FIG. 6 shows two conventional FAX machines 400a, 400b communicating over respective telephone lines 410, 412 through the public switched telephone network (PSTN) 400.
In particular, as shown in FIG. 6, each FAX machine 400a, 400b includes a respective, conventional FAX modem 402a, 402b which picks-up or takes the respective telephone line 410, 412 off-hook and initiates a handshaking of signals after a predetermined number of rings.
In particular, in operation, one FAX machine, e.g., 400a, sends an analog signal representing a facsimile image to the other FAX machine, e.g., 400b, using respective FAX modems 402a, 402b. In the given example, the FAX modem 402a of the sending FAX machine 400a converts scanned images of document pages into an analog FAX signal, which is appropriately conditioned and transmitted by that FAX modem 402a over its respective telephone line 410 to a synchronized and receiving FAX machine 400b. The analog FAX signal is switched through the PSTN 400 using digital transmission and other transmission media as necessary. The FAX modem 402b of the receiving FAX machine 400b converts the transmitted analog signal back into reproduced images for printing.
FIG. 7 shows a conventional method of automatically receiving a FAX message by taking a telephone line off-hook and initiating reception of a FAX message after a predetermined number of ring signals are detected.
In particular, as shown in step 702 of FIG. 7, an incoming call ring signal is detected, and the ring signals are counted in step 704.
Step 706 determines the point at which a pre-configured number of ring signals (e.g., four (4) ring signals) have occurred.
After the predetermined number of ring signals have occurred, the FAX machine answers the incoming call (presuming that the user has not already answered the telephone call at another telephonic device) by controlling a telephone line interface to draw sufficient current from the telephone line to take the telephone line “off-hook”, as shown in step 708.
After taking the telephone line off-hook, the receiving FAX machine initiates its part of handshaking with the incoming FAX signal, as shown in step 710.
After the handshaking between sending and receiving FAX machines has accomplished appropriate synchronization, the incoming FAX signal is received and re-imaged (and printed if desired), as shown in step 712.
Many users wish to add a fax machine to an existing voice line so as not to incur the expense of adding a second telephone line for dedicated use by a FAX machine. Using a shared, common telephone line, the user must either set their FAX machine to always answer after a predetermined number of rings, e.g., after a fourth ring. However, this then makes any telephone answering device or central office voice mail on the same telephone line inoperable because they typically operate using the same ring-count principle.
Alternatively, the user must set their FAX machine to only receive when it is started manually by the user when he or she answers the incoming telephone call and recognizes that a fax machine is on the other end. However, this techniques makes a FAX machine inoperable when no one is available to manually start it.
Thus, when a conventional FAX machine shares a telephone line with a separate telephonic device, e.g., a telephone answering system, typically only one of the devices, e.g., either the FAX machine or the telephone answering system, can be placed in an automatic mode wherein automatic answering and reception of an incoming message is automatically initiated and received after a predetermined number of ring signals are detected. This causes an inconvenience and inefficiency in the operation of a home or business with respect to FAX messages and, e.g., voice messages.
Some approaches have been previously undertaken to allow automation of both a FAX machine and another telephonic device (e.g., a telephone answering device).
For instance, some FAX machines can be set to answer on a distinctive ring. However, distinctive ring requires additional service ordered from the relevant telephone company, reducing or eliminating the cost savings associated with sharing a common telephone line. Moreover, the user typically also ends up with an additional phone number associated with the distinctive ring to distribute to would-be senders of FAX messages. Lastly, since a user simply doesn't know which calls will be from a FAX machine, distinctive ringing is not always useful.
Other conventional FAX machines include Caller ID displays (e.g. those available from PANASONIC™ or BROTHER™ to assist a user in determining whether or not activation of FAX reception should be manually initiated either before the pre-configured number of rings if set for automatic reception, or at any time if the FAX machine is set for manual reception.
Yet other conventional FAX machines have a built-in digital telephone answering device (TAD), which can answer and receive an incoming fax or record a voice message based on far end signals. A FAX machine having an integrated telephone answering device may satisfy some customer's needs, but the inclusion of a suitable amount of storage memory and provision of the TAD features typically add significantly to the cost of a system. Moreover, many users already have a separate TAD when purchasing a FAX machine, and prefer to use the original, separate telephone answering device. Furthermore, those who prefer a more advanced (e.g. full featured) TAD than those typically provided as an added feature of a FAX machine, and/or those who subscribe to a central office voice mail service would not be able to take advantage of the integrated TAD feature. These same problems are associated with computer FAX/voice modems which integrate FAX functionality with telephone answering device functionality within the same device.
The present invention frees a FAX machine to operate separately from other devices (e.g., from telephone answering devices), and more intelligently no matter what else may be connected to the telephone service. Eliminating the requirement to integrate a telephone answering device within a FAX machine (or together within a computer) to provide automation for both the FAX machine and another device such as a telephone answering device reduces the costs of the FAX machine.
There is a need for a FAX machine which automatically answers an incoming FAX call, particularly without disabling other telephonic device sharing a common telephone line.